A denial-of-service (DoS) attack involves actions to make a computer resource, such as an Internet website or service, inaccessible or otherwise unavailable to its intended users. Generally, such attacks involve measures by a third party to prevent a computer resource from functioning or negatively affecting the efficiency of the resource by keeping the web server resources busy with minimal use of network and client resources to prevent detection. A common type of DoS attack involves flooding a targeted resource with communication requests so that the requests burden the targeted resource, thereby making the resource slow to respond to legitimate requests or rendering the resource unresponsive.
Slowloris is a type of DoS attack that involves a single machine rendering a web server unavailable using minimal bandwidth. Specifically, slowloris attacks keep multiple connections to a target web server open and holds the connections open for as long as possible, resulting in the consumption of computation resources that would otherwise be available for the intended users of the web server.